JPH0569576B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a roller compactor for compressing particulate chemicals, particularly salts, into sheets. The compactor includes synchronously driven rollers with forming surfaces, a screw conveyor for feeding particulate chemical product into the nip between the rollers, a wedge-shaped wall member, an adjustment rod, and a wedge-shaped The wall member closes the roller gap on both sides in the axial direction and is in contact with the outer periphery of the end face of the roller, and the adjustment rod acts parallel to the roller axis to appropriately position the wall member. It has been adapted.

A device similar to the roller compactor of the present invention has been used in the method described in US Pat. No. 4,439,384. In this known method, the material to be compacted is charged at a temperature above 125°C, and the roller surface is kept at a temperature below 80°C. This method can be used to produce high-strength sheets from fine-grained salts with normal particle size distribution characteristics, which are ground or crushed into highly abrasion-resistant powders.

A particular problem in compacting finely divided salts, especially potash salts, is that the material with a high air content fed into the roller compactor is difficult to compress, as the salt to be compacted is deaerated during compaction in the interroller gaps. It is generally known that this poses increasing difficulties as the particle size decreases (see, for example, West German Patent Application No. 1250799 or the magazine "Aufbeiertungstechnik", 1967). No. 2, 80
~84 pages). That is, a consistent sheet across the roller width will not be formed on a compactor with smooth rollers. With a smooth roller, at most circumferentially extending ribbons of compressed material appear, between which there is uncompacted or only slightly compressed material. These intermediate areas of uncompressed material act as air bleed passages.

Roller compactors for compacting finely divided salt are usually equipped with compaction rollers having a relatively large working width. The working width is usually equal to the roller diameter, but it is advantageous if it is larger than the roller diameter. For example, for the compaction of finely divided salt, roller compactors have roller diameters of 1000 mm and working widths of 1250 mm are common. With such a compactor five screw conveyors are provided, the outlets of these screw conveyors are arranged side by side,
and are alternately inclined with respect to the vertical plane passing through the roller gap. 75-85% with particle size smaller than 0.4 mm (35 mesh) and 0.2 mm (65 mesh)
In the case of finely divided salts with a particle size distribution of 40% smaller than 40%, only sheets of insufficient quality can be produced even if the compression forces are significantly increased. For example, at an input power of 110-130A, a useful sheet produced with a compression force significantly above the normal compression force of 45-55kN per cm of roller width will produce approximately
It was 25t.

The object of the present invention is to provide a roller compactor that is capable of compressing granules, even very finely divided salt, into high-quality sheets with which granules with high abrasion resistance can be produced. be.

It is also an object of the invention to provide a roller compactor that can be operated effectively with low power inputs under normal compaction forces.

Means of the present invention for solving the above problems are as follows:
In a roller compactor of the type mentioned at the outset, a compactor frame is provided with an upper and a lower frame member, which are juxtaposed in the compactor frame and have horizontal axes parallel to each other and are driven by two motors. A roller body is provided, the axial end of the roller being rotatably supported in a rolling bearing within a bearing casing, the bearing casing positioning the roller between the upper and lower frame members. one of the rollers is movable together with the bearing casing between the upper and lower frame members, each roller body having two molded compression surfaces, the two compression surfaces being on the roller body; There is a mutual spacing in the axial direction, and between the two rollers
, each roller body having a radial shoulder at the axial end of each compression surface, each roller body having a radial shoulder at the axial end of each compression surface for feeding the particulate product into the space between the rollers of the two compression surfaces. At least one screw feeder means is provided for the two compression surfaces, and inner and outer wedge-shaped wall members are provided having inner and outer surfaces, the wall members having an inner surface and a radius. radial shoulders, closing the gap between the rollers in the axial direction of the rollers at each end of each compression surface, and applying pressure to the outer surface to support the wedge-shaped wall member against the radial shoulders. means for applying pressure to support the inner wedge-shaped wall member against the shoulder between two compression surfaces facing each other; a vertically adjustable bar disposed vertically between the wall members and within the space such that the bar contacts a corresponding wedge-shaped surface provided on the outside of both inner wall members; provided with a fitted wedge-shaped surface,
The bar is adapted to support the inner wedge-shaped wall member on the adjacent shoulder.

The present invention will be explained in detail below using experimental examples shown in the drawings.

The illustrated roller compactor has a basic construction of a known type. The compactor comprises two synchronously driven compaction rollers 2, 4 arranged side by side, the compaction rollers being mounted in a frame 6 in the usual manner. The ends of the compression roller are journalled in roller bearings in a bearing casing 8, by means of which the compression roller is arranged between the upper and lower frame members. One of the compression rollers is movable together with the bearing casing.

The compression rollers 2, 4 each have compression surfaces spaced apart from each other in the axial direction of the roller body. In the preferred embodiment shown, the compression surface is the cylindrical outer surface of the rings 28, 28A, which are advantageously positioned and secured to the roller body by a shrink fit. These rings 28, 28A have a radial shoulder 27, 2 at each end.
9; has 27A and 29A. Alternatively, a suitable ring with radial shoulders can be manufactured integrally with the core roller body. In this case, the outer surface of each ring integral with the roller body can be provided with a wear-resistant outer working surface by means such as welding.

Disposed between the upper frame members 10 is a bridge 12 on which a screw feeder or screw conveyor is mounted as shown in FIG. The screw feeder casing 14 constitutes a separate charging hopper for each screw feeder. The granular material to be compacted is fed into the roller nip via these charging hoppers. The charging hoppers 14 are directly adjacent to each other in the direction of the roller axis. Alternatively, the screw feeders are inclined in opposite directions with respect to a plane E passing through the center of the roll nip. Plane E is perpendicular to the plane containing the axis of the roller. Details of screw feeders or screw conveyors are known to those skilled in the art. The fine particulate material to be compacted, in particular salt (hereinafter referred to as "salt"), enters the intermediate bunker 18 through the inlet 16. A screw feeder transports salt from the bunker into the roller gap. The end of the charging hopper 14 is fixed within the plate 20. The plate is this plate 20,
The compression surface of the rollers and the gap between the rollers constitute a supply zone, and the upper surface of this supply zone is closed to form a seal.

Each end of the compression rollers 2, 4 is provided with a wedge-shaped outer wall member 22, which provides a termination for the feed zone by abutting a radially outer shoulder of a ring on the roller body. forming a seal. Wall member 22 is adjustably positioned and biased by horizontal thrust bolts 24, 25, 26, 24A, 25A, 26A. These thrust bolts are mounted in the frame of the compactor in the area between the bearing casings 8.

Two rings 2 as shown in fig.
8 and 28A are provided on each roller body 2 and 4 at intervals (or in parallel) in the axial direction. The wedge-shaped wall member 22 rests on the opposite outer shoulders 27, 27A of these rings. Furthermore, two wedge-shaped inner wall elements 30, 30A abut mutually facing shoulders 29, 29A at the inner ends of the two rings 28, 28A.

To force and adjust these wedge-shaped wall members 30, 30A into position, three pull rods 34, 35, 36 (two of which have their upper ends shown in FIG. 1) are used. a bridge member 32 arranged laterally with respect to the bridge 12 and advantageously mounted on the bridge;
are installed side by side. The drawbar 36 is advantageously arranged in the plane E, and the other two drawbars (only one of which is visible in FIGS. 1 and 2) are arranged on either side of the plane E. There is. The drawbar 36, which is arranged in the plane E, carries at its lower end a wedge-shaped or conical collar 38, which has a corresponding conical shape on the outer surface in the lower region of the inner wedge-shaped wall member 30, 30A. or wedge-shaped surface 4
Works with 0.40A. two outer pull bars 3
4, 35 are each provided with a corresponding conical or wedge-shaped collar 42, which collar 42 is connected to the wall member 3.
Corresponding conical or wedge-shaped surfaces 43, 43A and 4 located within the upper range of 0,30A
Collaborate with 4,44A. Wedge-shaped wall members 30, 30
The contact pressure against A is applied to the pull rod 3 by nuts 46, 46A supported on the upper surface of the bridge member 32.
This is done by vertical adjustment of 4,36.
In this way the pull rods 34, 35 are connected to the collar 4.
2.42A also has a handle adjustment and thrust bolt 2
5 and 26, and the pull rod 36 also has a collar 38 for adjustment and thrust bolt 24.
fulfills the functions of A thrust bar can also be provided instead of a pull bar.

By providing two axially spaced rings 28 with outer working or compression surfaces, the overall width B of the roller body is divided into two working widths b. For example, B may be 2.5b as shown, so the spacing between the two ring widths has a width of 1/2b.

Compared to conventional roller compactors with an active width B (B = 1250 mm, for example), the effective active width of the two compaction rollers 2, 4 is reduced to 2b in the described design. This represents a 20% reduction in effective action width.

Two screw feeders (their charging hoppers 1
4) are respectively assigned to two rings 28, 28A. As shown in FIG. 1, bridge member 32 is positioned between two adjacent charging hoppers 14 of two adjacent screw feeders.

By using two rings, each with axis b equal to 0.4B, it is possible to achieve higher compaction forces compared to known roller compactors with a single ring and working width B. For example, in a roller compactor originally designed to have an action width B and a compression force of 55 kN/cm, 20%
A high compression force, ie about 66 kN/cm, can be obtained with the same compression load.

A roller compactor (compactor A) according to the prior art with 5 screw feeders, having a roller diameter of 1000 mm and a working width B of 1250 mm and a total working width of 2 rings of 0.8 B, each ring having 2
In a test comparing a roller compactor according to the invention (compactor B) with two screw feeders, it was found that when compactor B was operated with a compaction force within the design range of compactor A, i.e.
It has been found that when operating with compressive forces on the order of 66 kN/cm, significant improvements in production rates can be achieved with significantly reduced power inputs and significant improvements in sheet quality. High quality continuous sheets with a thickness of 15-16 mm were produced without difficulty using compactor B. Granules produced from these sheets have high abrasion resistance.

Using compactor A, the compaction force exceeded 66kN/cm, reaching the safe limit of this compactor.
Particle size smaller than 0.4 mm (35 mesh)75
It was possible to achieve a production rate of about 25 tons/hour of granules from very fine potash salts with a particle size distribution of ~85% and 40% of particle sizes smaller than 0.2 mm (65 mesh). 110 for compactor A
A power input of ~130A was measured. In the case of compactor B, starting from the same salt, the production rate was approximately 35 tons of granules/hour with a power input of 60-70 A. In other words, a 20% increase in production rate was obtained with a reduction in input by approximately 50%. The compactor according to the invention is distinguished by extremely quiet operation with minimal vibrations.
Compactor B is equipped with only four screw feeders and therefore has a smaller supply capacity than compactor A.
Increased throughput was achieved despite operating at 80% capacity.

For the above tests, the compression surface of the ring of compactor A had a thin wafer compact with a molding depth of 5 mm, and the compression surface of compactor B had a compaction surface of one of the rings as shown in FIG. It has an upright rib welded to the compression surface.

A further increase in output can be achieved by a special configuration of the ribs on the compression surface of the roller, as one of the compression surfaces is shown in FIG. The ribs (or moldings) are ribs 4 with interruptions in the form of arrowheads with arrowhead tips in the direction of rotation of the rollers.
8, the rollers convey the sheet product downwards.

Advantageously, the arrowhead tip 50, which indicates the direction of rotation of the compactor rollers, has a closed shape. The arms of these arrowhead tips 50 are followed by an arm portion 54 after a break 52 . Advantageously, two such shaped bodies 48, 48A (having the same shape and whose arms 54 adjoin a cavity 56 at their ends facing each other) are arranged side by side, i.e. along the axial direction of the rollers. It is provided. The arms 54 arranged near the shoulders of the ring are advantageously at a small distance from the shoulders or end faces of the ring, so that there is also no air space between these arms and the respective wall member 22, 30 closing the roller gap. There is a place. The height h of the ribs built-up welded onto the outer ring or compression surface is approximately 3 mm. The angle α of the arrowhead tip is advantageously 130° to 150°
of the order of 140°, advantageously approximately 140°.

As a result of the configuration of the shaped bodies or ribs described above, the air trapped within the material flows along the arrowhead-shaped ribs and escapes through the rib interruptions 52, 56. This results in a significant improvement in air removal of the material and results in a very uniform and well-compacted sheet.

[Brief explanation of the drawing]

FIG. 1 shows a second roller compactor according to the present invention.
2 is a sectional view taken along the line 1-1 in the figure, FIG. 2 is a sectional view taken along the line - in FIG. 1, and FIG. 3 is an enlarged plan view showing ribs on the compression surface. 2, 4... Compression roller, 6... Frame, 8...
... Bearing casing, 10, 10A ... Frame member, 12 ... Bridge, 14 ... Charging hopper, 1
6... Entrance, 18... Bunker, 20... Plate, 22, 30, 30A... Wall member, 24, 24
A, 25, 25A, 26, 26A... Thrust bolt, 27, 27A, 29, 29A... Shoulder, 2
8, 28A...Ring, 32...Bridge member,
34, 35, 36... tension rod, 38, 42...
Color, 40, 40A, 43, 43A, 44, 4
4A...Surface, 46, 46A...Nut, 48...
...Rib, 50...Arrowhead tip, 52...Interruption part,
54... Arm part, 56... Blank space.

Claims (1)

[Claims] 1. A roller compactor for compressing fine particulate chemical products into a sheet, comprising: a compactor frame having upper and lower frame members arranged side by side within the compactor frame; A roller body is provided which has horizontal axes parallel to each other and is driven by two motors, and the axial end of the roller is rotatably supported in a rolling bearing in a bearing casing. The rollers are arranged by means of the casing between the upper and lower frame members, one of the rollers being movable together with the bearing casing between the upper and lower frame members, each roller body having two molded the two compression surfaces are spaced apart from each other in the axial direction on the roller body, and the distance between the two rollers is
, each roller body having a radial shoulder at the axial end of each compression surface, each roller body having a radial shoulder at the axial end of each compression surface for feeding particulate product into the space between the rollers of the two compression surfaces. At least one screw feeder means is provided for the two compression surfaces, and inner and outer wedge-shaped wall members are provided having inner and outer surfaces, the wall members having an inner surface and a radius. radial shoulders, closing the gap between the rollers in the axial direction of the rollers at each end of each compression surface, and applying pressure to the outer surface to support the wedge-shaped wall member against the radial shoulders. means for applying pressure to support the inner wedge-shaped wall member against the shoulder between two compression surfaces facing each other; a bar vertically disposed within the space between the wall members and vertically adjustable such that the bar contacts a corresponding wedge-shaped surface provided on the outside of both inner wall members; provided with a fitted wedge-shaped surface,
A roller compactor for compressing finely divided salt into a sheet, characterized in that the bar is adapted to support an inner wedge-shaped wall member on an adjacent shoulder. 2. The roller compactor according to claim 1, wherein the compression surface is the outer peripheral surface of a cylindrical ring. 3. Claim 1, wherein the compressed surface comprises a thin molded body.
Roller compactor as described. 4. The thin molded body has an arrowhead-shaped rib with an interruption pointing in the direction of rotation of the roller body;
A roller compactor according to claim 3. 5. The roller compactor according to claim 4, wherein the angle of the tip of the arrowhead-shaped rib is 130° to 150°. 6. The roller compactor of claim 4, wherein each rib is axially zigzag and includes two spaced apart arrowhead tips oriented in the direction of rotation. 7. The roller compactor of claim 6, wherein the rib has a circumferentially oriented closed arrowhead tip. 8. The roller compactor of claim 4, wherein the ribs are welded onto the compression surface of the ring at a height of 3 mm. 9. The roller compactor of claim 1, wherein the compaction surface has an axial width of about 450-550 mm. 10. The roller compactor of claim 1, wherein the screw feeder associated with each compaction surface has a respective separate charging hopper. 11 The compression surfaces have an axial width of approximately 450 to 550 mm, and two screw feeders are arranged for each compression surface, and the feeder associated with the two compression surfaces has a separate 2. The roller compactor of claim 1, further comprising a charging hopper. 12. The roller compactor of claim 1, wherein the wedge-shaped surface is a conical surface. 13. The roller compactor of claim 2, wherein the cylindrical ring is shrink-fitted onto the cylindrical surface of the roller body.